1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2011 Kionix, Inc.
4 * Written by Chris Hudson <chudson@kionix.com>
5 */
6
7#include <linux/delay.h>
8#include <linux/i2c.h>
9#include <linux/input.h>
10#include <linux/interrupt.h>
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/input/kxtj9.h>
14
15#define NAME			"kxtj9"
16#define G_MAX			8000
17/* OUTPUT REGISTERS */
18#define XOUT_L			0x06
19#define WHO_AM_I		0x0F
20/* CONTROL REGISTERS */
21#define INT_REL			0x1A
22#define CTRL_REG1		0x1B
23#define INT_CTRL1		0x1E
24#define DATA_CTRL		0x21
25/* CONTROL REGISTER 1 BITS */
26#define PC1_OFF			0x7F
27#define PC1_ON			(1 << 7)
28/* Data ready funtion enable bit: set during probe if using irq mode */
29#define DRDYE			(1 << 5)
30/* DATA CONTROL REGISTER BITS */
31#define ODR12_5F		0
32#define ODR25F			1
33#define ODR50F			2
34#define ODR100F		3
35#define ODR200F		4
36#define ODR400F		5
37#define ODR800F		6
38/* INTERRUPT CONTROL REGISTER 1 BITS */
39/* Set these during probe if using irq mode */
40#define KXTJ9_IEL		(1 << 3)
41#define KXTJ9_IEA		(1 << 4)
42#define KXTJ9_IEN		(1 << 5)
43/* INPUT_ABS CONSTANTS */
44#define FUZZ			3
45#define FLAT			3
46/* RESUME STATE INDICES */
47#define RES_DATA_CTRL		0
48#define RES_CTRL_REG1		1
49#define RES_INT_CTRL1		2
50#define RESUME_ENTRIES		3
51
52/*
53 * The following table lists the maximum appropriate poll interval for each
54 * available output data rate.
55 */
56static const struct {
57	unsigned int cutoff;
58	u8 mask;
59} kxtj9_odr_table[] = {
60	{ 3,	ODR800F },
61	{ 5,	ODR400F },
62	{ 10,	ODR200F },
63	{ 20,	ODR100F },
64	{ 40,	ODR50F  },
65	{ 80,	ODR25F  },
66	{ 0,	ODR12_5F},
67};
68
69struct kxtj9_data {
70	struct i2c_client *client;
71	struct kxtj9_platform_data pdata;
72	struct input_dev *input_dev;
73	unsigned int last_poll_interval;
74	u8 shift;
75	u8 ctrl_reg1;
76	u8 data_ctrl;
77	u8 int_ctrl;
78};
79
80static int kxtj9_i2c_read(struct kxtj9_data *tj9, u8 addr, u8 *data, int len)
81{
82	struct i2c_msg msgs[] = {
83		{
84			.addr = tj9->client->addr,
85			.flags = tj9->client->flags,
86			.len = 1,
87			.buf = &addr,
88		},
89		{
90			.addr = tj9->client->addr,
91			.flags = tj9->client->flags | I2C_M_RD,
92			.len = len,
93			.buf = data,
94		},
95	};
96
97	return i2c_transfer(tj9->client->adapter, msgs, 2);
98}
99
100static void kxtj9_report_acceleration_data(struct kxtj9_data *tj9)
101{
102	s16 acc_data[3]; /* Data bytes from hardware xL, xH, yL, yH, zL, zH */
103	s16 x, y, z;
104	int err;
105
106	err = kxtj9_i2c_read(tj9, XOUT_L, (u8 *)acc_data, 6);
107	if (err < 0)
108		dev_err(&tj9->client->dev, "accelerometer data read failed\n");
109
110	x = le16_to_cpu(acc_data[tj9->pdata.axis_map_x]);
111	y = le16_to_cpu(acc_data[tj9->pdata.axis_map_y]);
112	z = le16_to_cpu(acc_data[tj9->pdata.axis_map_z]);
113
114	x >>= tj9->shift;
115	y >>= tj9->shift;
116	z >>= tj9->shift;
117
118	input_report_abs(tj9->input_dev, ABS_X, tj9->pdata.negate_x ? -x : x);
119	input_report_abs(tj9->input_dev, ABS_Y, tj9->pdata.negate_y ? -y : y);
120	input_report_abs(tj9->input_dev, ABS_Z, tj9->pdata.negate_z ? -z : z);
121	input_sync(tj9->input_dev);
122}
123
124static irqreturn_t kxtj9_isr(int irq, void *dev)
125{
126	struct kxtj9_data *tj9 = dev;
127	int err;
128
129	/* data ready is the only possible interrupt type */
130	kxtj9_report_acceleration_data(tj9);
131
132	err = i2c_smbus_read_byte_data(tj9->client, INT_REL);
133	if (err < 0)
134		dev_err(&tj9->client->dev,
135			"error clearing interrupt status: %d\n", err);
136
137	return IRQ_HANDLED;
138}
139
140static int kxtj9_update_g_range(struct kxtj9_data *tj9, u8 new_g_range)
141{
142	switch (new_g_range) {
143	case KXTJ9_G_2G:
144		tj9->shift = 4;
145		break;
146	case KXTJ9_G_4G:
147		tj9->shift = 3;
148		break;
149	case KXTJ9_G_8G:
150		tj9->shift = 2;
151		break;
152	default:
153		return -EINVAL;
154	}
155
156	tj9->ctrl_reg1 &= 0xe7;
157	tj9->ctrl_reg1 |= new_g_range;
158
159	return 0;
160}
161
162static int kxtj9_update_odr(struct kxtj9_data *tj9, unsigned int poll_interval)
163{
164	int err;
165	int i;
166
167	/* Use the lowest ODR that can support the requested poll interval */
168	for (i = 0; i < ARRAY_SIZE(kxtj9_odr_table); i++) {
169		tj9->data_ctrl = kxtj9_odr_table[i].mask;
170		if (poll_interval < kxtj9_odr_table[i].cutoff)
171			break;
172	}
173
174	err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0);
175	if (err < 0)
176		return err;
177
178	err = i2c_smbus_write_byte_data(tj9->client, DATA_CTRL, tj9->data_ctrl);
179	if (err < 0)
180		return err;
181
182	err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
183	if (err < 0)
184		return err;
185
186	return 0;
187}
188
189static int kxtj9_device_power_on(struct kxtj9_data *tj9)
190{
191	if (tj9->pdata.power_on)
192		return tj9->pdata.power_on();
193
194	return 0;
195}
196
197static void kxtj9_device_power_off(struct kxtj9_data *tj9)
198{
199	int err;
200
201	tj9->ctrl_reg1 &= PC1_OFF;
202	err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
203	if (err < 0)
204		dev_err(&tj9->client->dev, "soft power off failed\n");
205
206	if (tj9->pdata.power_off)
207		tj9->pdata.power_off();
208}
209
210static int kxtj9_enable(struct kxtj9_data *tj9)
211{
212	int err;
213
214	err = kxtj9_device_power_on(tj9);
215	if (err < 0)
216		return err;
217
218	/* ensure that PC1 is cleared before updating control registers */
219	err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0);
220	if (err < 0)
221		return err;
222
223	/* only write INT_CTRL_REG1 if in irq mode */
224	if (tj9->client->irq) {
225		err = i2c_smbus_write_byte_data(tj9->client,
226						INT_CTRL1, tj9->int_ctrl);
227		if (err < 0)
228			return err;
229	}
230
231	err = kxtj9_update_g_range(tj9, tj9->pdata.g_range);
232	if (err < 0)
233		return err;
234
235	/* turn on outputs */
236	tj9->ctrl_reg1 |= PC1_ON;
237	err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
238	if (err < 0)
239		return err;
240
241	err = kxtj9_update_odr(tj9, tj9->last_poll_interval);
242	if (err < 0)
243		return err;
244
245	/* clear initial interrupt if in irq mode */
246	if (tj9->client->irq) {
247		err = i2c_smbus_read_byte_data(tj9->client, INT_REL);
248		if (err < 0) {
249			dev_err(&tj9->client->dev,
250				"error clearing interrupt: %d\n", err);
251			goto fail;
252		}
253	}
254
255	return 0;
256
257fail:
258	kxtj9_device_power_off(tj9);
259	return err;
260}
261
262static void kxtj9_disable(struct kxtj9_data *tj9)
263{
264	kxtj9_device_power_off(tj9);
265}
266
267static int kxtj9_input_open(struct input_dev *input)
268{
269	struct kxtj9_data *tj9 = input_get_drvdata(input);
270
271	return kxtj9_enable(tj9);
272}
273
274static void kxtj9_input_close(struct input_dev *dev)
275{
276	struct kxtj9_data *tj9 = input_get_drvdata(dev);
277
278	kxtj9_disable(tj9);
279}
280
281/*
282 * When IRQ mode is selected, we need to provide an interface to allow the user
283 * to change the output data rate of the part.  For consistency, we are using
284 * the set_poll method, which accepts a poll interval in milliseconds, and then
285 * calls update_odr() while passing this value as an argument.  In IRQ mode, the
286 * data outputs will not be read AT the requested poll interval, rather, the
287 * lowest ODR that can support the requested interval.  The client application
288 * will be responsible for retrieving data from the input node at the desired
289 * interval.
290 */
291
292/* Returns currently selected poll interval (in ms) */
293static ssize_t kxtj9_get_poll(struct device *dev,
294				struct device_attribute *attr, char *buf)
295{
296	struct i2c_client *client = to_i2c_client(dev);
297	struct kxtj9_data *tj9 = i2c_get_clientdata(client);
298
299	return sprintf(buf, "%d\n", tj9->last_poll_interval);
300}
301
302/* Allow users to select a new poll interval (in ms) */
303static ssize_t kxtj9_set_poll(struct device *dev, struct device_attribute *attr,
304						const char *buf, size_t count)
305{
306	struct i2c_client *client = to_i2c_client(dev);
307	struct kxtj9_data *tj9 = i2c_get_clientdata(client);
308	struct input_dev *input_dev = tj9->input_dev;
309	unsigned int interval;
310	int error;
311
312	error = kstrtouint(buf, 10, &interval);
313	if (error < 0)
314		return error;
315
316	/* Lock the device to prevent races with open/close (and itself) */
317	mutex_lock(&input_dev->mutex);
318
319	disable_irq(client->irq);
320
321	/*
322	 * Set current interval to the greater of the minimum interval or
323	 * the requested interval
324	 */
325	tj9->last_poll_interval = max(interval, tj9->pdata.min_interval);
326
327	kxtj9_update_odr(tj9, tj9->last_poll_interval);
328
329	enable_irq(client->irq);
330	mutex_unlock(&input_dev->mutex);
331
332	return count;
333}
334
335static DEVICE_ATTR(poll, S_IRUGO|S_IWUSR, kxtj9_get_poll, kxtj9_set_poll);
336
337static struct attribute *kxtj9_attrs[] = {
338	&dev_attr_poll.attr,
339	NULL
340};
341
342static umode_t kxtj9_attr_is_visible(struct kobject *kobj,
343				     struct attribute *attr, int n)
344{
345	struct device *dev = kobj_to_dev(kobj);
346	struct i2c_client *client = to_i2c_client(dev);
347
348	return client->irq ? attr->mode : 0;
349}
350
351static struct attribute_group kxtj9_group = {
352	.attrs = kxtj9_attrs,
353	.is_visible = kxtj9_attr_is_visible,
354};
355__ATTRIBUTE_GROUPS(kxtj9);
356
357static void kxtj9_poll(struct input_dev *input)
358{
359	struct kxtj9_data *tj9 = input_get_drvdata(input);
360	unsigned int poll_interval = input_get_poll_interval(input);
361
362	kxtj9_report_acceleration_data(tj9);
363
364	if (poll_interval != tj9->last_poll_interval) {
365		kxtj9_update_odr(tj9, poll_interval);
366		tj9->last_poll_interval = poll_interval;
367	}
368}
369
370static void kxtj9_platform_exit(void *data)
371{
372	struct kxtj9_data *tj9 = data;
373
374	if (tj9->pdata.exit)
375		tj9->pdata.exit();
376}
377
378static int kxtj9_verify(struct kxtj9_data *tj9)
379{
380	int retval;
381
382	retval = kxtj9_device_power_on(tj9);
383	if (retval < 0)
384		return retval;
385
386	retval = i2c_smbus_read_byte_data(tj9->client, WHO_AM_I);
387	if (retval < 0) {
388		dev_err(&tj9->client->dev, "read err int source\n");
389		goto out;
390	}
391
392	retval = (retval != 0x07 && retval != 0x08) ? -EIO : 0;
393
394out:
395	kxtj9_device_power_off(tj9);
396	return retval;
397}
398
399static int kxtj9_probe(struct i2c_client *client)
400{
401	const struct kxtj9_platform_data *pdata =
402			dev_get_platdata(&client->dev);
403	struct kxtj9_data *tj9;
404	struct input_dev *input_dev;
405	int err;
406
407	if (!i2c_check_functionality(client->adapter,
408				I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA)) {
409		dev_err(&client->dev, "client is not i2c capable\n");
410		return -ENXIO;
411	}
412
413	if (!pdata) {
414		dev_err(&client->dev, "platform data is NULL; exiting\n");
415		return -EINVAL;
416	}
417
418	tj9 = devm_kzalloc(&client->dev, sizeof(*tj9), GFP_KERNEL);
419	if (!tj9) {
420		dev_err(&client->dev,
421			"failed to allocate memory for module data\n");
422		return -ENOMEM;
423	}
424
425	tj9->client = client;
426	tj9->pdata = *pdata;
427
428	if (pdata->init) {
429		err = pdata->init();
430		if (err < 0)
431			return err;
432	}
433
434	err = devm_add_action_or_reset(&client->dev, kxtj9_platform_exit, tj9);
435	if (err)
436		return err;
437
438	err = kxtj9_verify(tj9);
439	if (err < 0) {
440		dev_err(&client->dev, "device not recognized\n");
441		return err;
442	}
443
444	i2c_set_clientdata(client, tj9);
445
446	tj9->ctrl_reg1 = tj9->pdata.res_12bit | tj9->pdata.g_range;
447	tj9->last_poll_interval = tj9->pdata.init_interval;
448
449	input_dev = devm_input_allocate_device(&client->dev);
450	if (!input_dev) {
451		dev_err(&client->dev, "input device allocate failed\n");
452		return -ENOMEM;
453	}
454
455	input_set_drvdata(input_dev, tj9);
456	tj9->input_dev = input_dev;
457
458	input_dev->name = "kxtj9_accel";
459	input_dev->id.bustype = BUS_I2C;
460
461	input_dev->open = kxtj9_input_open;
462	input_dev->close = kxtj9_input_close;
463
464	input_set_abs_params(input_dev, ABS_X, -G_MAX, G_MAX, FUZZ, FLAT);
465	input_set_abs_params(input_dev, ABS_Y, -G_MAX, G_MAX, FUZZ, FLAT);
466	input_set_abs_params(input_dev, ABS_Z, -G_MAX, G_MAX, FUZZ, FLAT);
467
468	if (client->irq <= 0) {
469		err = input_setup_polling(input_dev, kxtj9_poll);
470		if (err)
471			return err;
472	}
473
474	err = input_register_device(input_dev);
475	if (err) {
476		dev_err(&client->dev,
477			"unable to register input polled device %s: %d\n",
478			input_dev->name, err);
479		return err;
480	}
481
482	if (client->irq) {
483		/* If in irq mode, populate INT_CTRL_REG1 and enable DRDY. */
484		tj9->int_ctrl |= KXTJ9_IEN | KXTJ9_IEA | KXTJ9_IEL;
485		tj9->ctrl_reg1 |= DRDYE;
486
487		err = devm_request_threaded_irq(&client->dev, client->irq,
488						NULL, kxtj9_isr,
489						IRQF_TRIGGER_RISING |
490							IRQF_ONESHOT,
491						"kxtj9-irq", tj9);
492		if (err) {
493			dev_err(&client->dev, "request irq failed: %d\n", err);
494			return err;
495		}
496	}
497
498	return 0;
499}
500
501static int kxtj9_suspend(struct device *dev)
502{
503	struct i2c_client *client = to_i2c_client(dev);
504	struct kxtj9_data *tj9 = i2c_get_clientdata(client);
505	struct input_dev *input_dev = tj9->input_dev;
506
507	mutex_lock(&input_dev->mutex);
508
509	if (input_device_enabled(input_dev))
510		kxtj9_disable(tj9);
511
512	mutex_unlock(&input_dev->mutex);
513	return 0;
514}
515
516static int kxtj9_resume(struct device *dev)
517{
518	struct i2c_client *client = to_i2c_client(dev);
519	struct kxtj9_data *tj9 = i2c_get_clientdata(client);
520	struct input_dev *input_dev = tj9->input_dev;
521
522	mutex_lock(&input_dev->mutex);
523
524	if (input_device_enabled(input_dev))
525		kxtj9_enable(tj9);
526
527	mutex_unlock(&input_dev->mutex);
528	return 0;
529}
530
531static DEFINE_SIMPLE_DEV_PM_OPS(kxtj9_pm_ops, kxtj9_suspend, kxtj9_resume);
532
533static const struct i2c_device_id kxtj9_id[] = {
534	{ NAME, 0 },
535	{ },
536};
537
538MODULE_DEVICE_TABLE(i2c, kxtj9_id);
539
540static struct i2c_driver kxtj9_driver = {
541	.driver = {
542		.name		= NAME,
543		.dev_groups	= kxtj9_groups,
544		.pm		= pm_sleep_ptr(&kxtj9_pm_ops),
545	},
546	.probe		= kxtj9_probe,
547	.id_table	= kxtj9_id,
548};
549
550module_i2c_driver(kxtj9_driver);
551
552MODULE_DESCRIPTION("KXTJ9 accelerometer driver");
553MODULE_AUTHOR("Chris Hudson <chudson@kionix.com>");
554MODULE_LICENSE("GPL");
555